Impeller-type air pumps or blowers are used in many environments or applications. Such a blower conventionally includes a housing defining a pumping chamber or cavity within which an impeller assembly is rotated. The impeller assembly is mounted on shaft means rotatably journaled within the housing and including radially projecting blades for drawing air into an inlet of the housing and out through an outlet. Bearings and seals are provided about the impeller shaft to journal the shaft within the housing and to prevent air leakage past the impeller except through its intended flow path.
One environment where blowers are used is in conjunction with a particle separator in environments of particle contamination. For instance, in aircraft applications, such as with helicopters, the vehicles may be used over sandy areas, such as deserts, and particle separators are used to prevent the intake of particle contaminated air from adversely effecting or damaging the engine of the helicopter. Such particle separators use blowers for their operation. A major problem concerns the introduction of particle contaminated air into the bearings of the blower impeller which could result in catastrophic failure of the bearing and, thus, eventual failure of the main engine itself.
This invention is directed to solving the above problem by providing a novel means for pressure balancing opposite sides of bearings in an impeller-type blower to prevent particle contaminants from infiltrating the bearing means and/or seal means.